I had the same problem. What I did to created the problem was altering my user password by doing a sudo passwd which worked fine; but the next day when I tried to login, was then stuck in the gdm login loop.

Then went to the virtual terminal using ctrl-alt-F1, logged in with my new pw, saw that home was empty, did a

ecryptfs-recover-private

and typed my OLD password. then my home was mounted again and so then could switch back to the graphical interface ctrl-F7 and login with the NEW password :)

Then it was possible to update my cryptfs password on a terminal with: